Its MC and not MS (Main Controller = your phantom).
I just restart and it goes away. I get this when i'm on concrete. Maybe rebar interference?

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I was occasionally getting the same thing, so now I just avoid taking off from concrete. I also noticed that the icon on the radar in the bottom left hand corner of the app wasn't pointing the correct way, when on the same piece of concrete. When I moved the bird to a grassy area everything was back to normal. So it must be rebar. So I avoid concrete when I can.

If you are surrounded by rebar, just use a non-metallic box to take off.
Or use a person and a do a release take-off. Just remember to full throttle up and let them know when to release. Last thing you want is to give a them a new haircut/face.